We formulate the optimal permutation problem (OPP) in a
pragmatic way by considering the correlation matrix \(B\)  showed in
Figure REF a describing the neuronal activity of \(N = 33\) 
neurons of the nematode C. elegans measured for three locomotory
tasks of the animal (forward, backward, turn) in ref. [1]}.
The choice of this particular dataset is useful to get an instrumental
view of the optimal permutation problem and how it relates to real-world
data, although we could formulate our mathematical theory completely
in abstracto as well. Thus, we emphasize that the optimal
permutation theory and algorithm we present here can be applied to
any square matrix of the most general form.
